1. Field of the Invention
The present invention relates to a lens arranging method for a lens array, and more specifically, to an autostereoscopic display apparatus using a light beam control device, such as a lens array.
2. Description of the Related Art
An autostereoscopic display apparatus (or, “autostereoscopic display,” hereafter) is capable of providing stereoscopic images that an observer can observe without using a special device such as glasses. Various methods for the autostereoscopic display are known including, for example, lenticular methods and holography methods. Basic principles of most of such methods are common in that light beam information incident on eyes of an observer is controlled to cause different types of light beam information are incident on the left and right eyes of the observer, whereby an autostereoscopic is implemented. As one method of autostereoscopic display, an integral photography method is known (see M. G. Lippmann, Epreuves reversibles donnant la sensation du relief, pp. 821-825, Vol. 7, J. de Phys, 1908).
With reference to FIG. 1, the integral photography method is configured of an image display device 1 and a lens array 3 formed of a large number of lenses 2. The integral photography method uses the plurality of lenses 2 to thereby generates a light spot 4 at an arbitrary site, in which a plurality of pixels are provided below the respective lenses 2, and one of the pixels indicates the light spot 4.
When the lens array 3 is seen from a view point A6 shown in FIG. 2 (horizontally in a cross sectional view taken along a dot line portion 5 shown in FIG. 1), pixels A7 are seen through respective lenses. When seen from a view point B8, pixels B9 are seen through respective lenses. Thus, the different pixels are seen from the left and right eyes, so that the stereogram can be implemented.
With the lens array, a similar autostereoscopic display can be configured by combination of a light beam control device array, in which a large number of light beam control devices for controlling light beams are arranged, with a flat display or an image display device for displaying images on films and the like, for example. Regarding the array arrangement of light beam control devices, there are employed many types, such as arrangement in a square matrix arrangement, closest filling arrangement for increasing the number of light beam control devices, or delta arrangement. In addition, in many cases, circular or hexagonal lenses are used in a lens array. As shown in FIG. 3, a displayable region 10 of the respective lens is the substantially the same in shape as a lens associated pixel 19. The lens associated pixel 19 contributes to the display of a stereoscopic image with an associated lens, and corresponds to the displayable region 10.
In addition, a technique is known'that has a lens array using ellipsoidal lenses to widen a view range (see Japanese Unexamined Patent Application Publication No. 07-7747 (or, 1995-7747)).